Parker also says Obama should 'evolve faster'

Steve Riggle, pastor of the 15,000 member Grace Community Church, wrote in an email to Parker on Friday, “Respectfully, if you cannot uphold the Texas constitution, then you should do the honorable thing and step down,” reported the Houston Chronicle.

Riggle asserts that Parker’s role in the coalition violates “the very constitution you were swearing to uphold.”

In response, Parker said “I do my duty to uphold the state Constitution and the U.S. Constitution. I swore an oath to that. I take that oath very seriously, but I have my First Amendment rights to free speech.”

“We all have the right to do that and I’m sorry that they (Riggle and his supporters) don’t understand the Constitution,” Parker said.

Parker has also said that President Barack “needs to evolve a little bit faster and is not clearly where I think he ought to be” on the issue of marriage equality.

In an interview with Michelangelo Signorile on SiriusXM radio, Parker said she agrees with activists who are pushing the Democratic National Committee to include marriage equality in this year’s party platform.

Riggle has also objected to a city memo that identified Parker’s long-term partner, Kathy Hubbard, as the “first lady” of Houston, calling the distinction “deeply disturbing.”

Parker was elected Mayor of Houston, the fourth largest U.S. city, in 2009; she was elected to a second term in November 2011. Parker and Hubbard have been together since 1990 and have three children.